arch/s390/net/bpf_jit.h

   1 /*
   2  * BPF Jit compiler defines
   3  *
   4  * Copyright IBM Corp. 2012,2015
   5  *
   6  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
   7  *            Michael Holzheu <holzheu@linux.vnet.ibm.com>
   8  */
   9
  10 #ifndef __ARCH_S390_NET_BPF_JIT_H
  11 #define __ARCH_S390_NET_BPF_JIT_H
  12
  13 #ifndef __ASSEMBLY__
  14
  15 #include <linux/filter.h>
  16 #include <linux/types.h>
  17
  18 extern u8 sk_load_word_pos[], sk_load_half_pos[], sk_load_byte_pos[];
  19 extern u8 sk_load_word[], sk_load_half[], sk_load_byte[];
  20
  21 #endif /* __ASSEMBLY__ */
  22
  23 /*
  24  * Stackframe layout (packed stack):
  25  *
  26  *                                  ^ high
  27  *            +---------------+     |
  28  *            | old backchain |     |
  29  *            +---------------+     |
  30  *            |   r15 - r6    |     |
  31  *            +---------------+     |
  32  *            | 4 byte align  |     |
  33  *            | tail_call_cnt |     |
  34  * BFP     -> +===============+     |
  35  *            |               |     |
  36  *            |   BPF stack   |     |
  37  *            |               |     |
  38  *            +---------------+     |
  39  *            | 8 byte skbp   |     |
  40  * R15+176 -> +---------------+     |
  41  *            | 8 byte hlen   |     |
  42  * R15+168 -> +---------------+     |
  43  *            | 4 byte align  |     |
  44  *            +---------------+     |
  45  *            | 4 byte temp   |     |
  46  *            | for bpf_jit.S |     |
  47  * R15+160 -> +---------------+     |
  48  *            | new backchain |     |
  49  * R15+152 -> +---------------+     |
  50  *            | + 152 byte SA |     |
  51  * R15     -> +---------------+     + low
  52  *
  53  * We get 160 bytes stack space from calling function, but only use
  54  * 12 * 8 byte for old backchain, r15..r6, and tail_call_cnt.
  55  */
  56 #define STK_SPACE       (MAX_BPF_STACK + 8 + 8 + 4 + 4 + 160)
  57 #define STK_160_UNUSED  (160 - 12 * 8)
  58 #define STK_OFF         (STK_SPACE - STK_160_UNUSED)
  59 #define STK_OFF_TMP     160     /* Offset of tmp buffer on stack */
  60 #define STK_OFF_HLEN    168     /* Offset of SKB header length on stack */
  61 #define STK_OFF_SKBP    176     /* Offset of SKB pointer on stack */
  62
  63 #define STK_OFF_R6      (160 - 11 * 8)  /* Offset of r6 on stack */
  64 #define STK_OFF_TCCNT   (160 - 12 * 8)  /* Offset of tail_call_cnt on stack */
  65
  66 /* Offset to skip condition code check */
  67 #define OFF_OK          4
  68
  69 #endif /* __ARCH_S390_NET_BPF_JIT_H */